Apparently the explorers are based around the historical characters so Spain and Portugal get a big head start while England have to make do with the Cabot's as explorer until nearly the Elisabethen age and they don't last long.
The advantage of this is that it's more real to the time which is really just saying that some countries have natural advantages over the others.
My best advice is to get your first explorer across the Atlantic via the Azores (I think it's the safest route) and head for the US coast but try to get him back for at least one more trip. Once you have found land you can set up trading posts which are cheaper than settlers and in the early days you're probably a bit cash strapped. They will, in any case, improve your chances of settling when you have more settlers and money.
Later on in the game you'll probably find yourself getting
a settler each year and you're also likely to have already got more information from gaining the Spanish and Portuguese maps. Often these will be gained from ships during the course of naval battles. This will give you plenty of places to set up trading posts and settlements for later.
If you have problems getting into a war with the Spanish try changing to Protestant if you're English. It might be a bit scary to start with and you will be lucky to come out of the mess completely unscathed but trust me, it's better in the long run. To improve your navy's chances in battle also try to get to level 5 technology before the war.
I guess the problem of getting into a war with Spain is unlikely to be great if you're playing France.
In the long run settlements are better than trading posts since they will normally give you ports at which you can dock your ships. Try to have at least one in North America and in Southern Africa by c1550 ready for a new batch of explorers to arrive just before the Elisabethen era.
After that, I've got no clue. I've only got to 1557
